Dialuminium titanium pentaoxide

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

31st July 2007 to 24th August, 2007.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study but GLP status unclear

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

Magnusson and Kilgmann method.

GLP compliance:

not specified

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Japan SLC, Co., Ltd.
- Age at study initiation: 9 weeks old.
- Weight at study initiation: 371.4 - 478.2 g
- Housing: The animals were housed in groups of five in suspended aluminium cages with stainless steel wire-mesh front and floor (W450 x D550 x H350mm). Cages were replaced once every week with washed and sterilized cages.
- Diet (e.g. ad libitum): Labo G Standard, Nosan Corporation, Japan provided ad libitum throughout the study.
- Water (e.g. ad libitum): Filtered tap water available ad libitum throughout the study.
- Acclimation period: 42 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24°C
- Humidity (%): 30 - 70%
- Air changes (per hr): More than 10 fresh air changes per hour.
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours dark.

IN-LIFE DATES: From: June 27th 2007 To: 24th August 2007.

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

Intradermal induction - Preliminary study: 5%, 2%, 1%, 0.5%, 0.2% and 0.1%.
Cutaneous application - Preliminary study: 25, 10 and 1%

Main study:
Induction: 5%
2nd Induction: 25%
Challenge: 25%.

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

Intradermal induction - Preliminary study: 5%, 2%, 1%, 0.5%, 0.2% and 0.1%.
Cutaneous application - Preliminary study: 25, 10 and 1%

Main study:
Induction: 5%
2nd Induction: 25%
Challenge: 25%.

No. of animals per dose:

Test groups: 10 animals per group.
Control group: 5 animals per group.

Details on study design:

RANGE FINDING TESTS:
A preliminary study was conducted to select the appropriate concentrations for induction and challenge. Two animals were intradermally treated with the test substance at 5%, 2%, 1%, 0.5%, 0.2% and 0.1% in water for injection and water for injection (0%) as a control. 0.1 mL was applied per site, with 7 doses per body. Observations were recorded 24 and 48 hours after injection, with no skin reactions recorded at any of the application sites.

Lint patches (2 cmx 2cm) saturated with 0.2 mL of the test substance at 25%, 10% and 1% in water were applied to 2 animals. Three doses were applied to each animal. Observations were recorded 24 and 48 hours after application, with no skin reactions recorded at any of the application sites.

The concentrations chosen for the main study were determined to be 5% for the 1st induction, 25% for the 2nd induction and 25% for the challenge application.

MAIN STUDY
A. INDUCTION EXPOSURE
The test animals received three intradermal injections of a 1:1 water in oil emulsion mixture of FCA and distilled water, 5% test substance suspension in water for injection and a 1:1 water in oil emulsion mixture of FCA and 10% test substance suspension in water for injection. 0.1mL was applied per site.
After 7 days, a lint patch, saturated with 0.4 mL of 25% test substance suspension in water for injection was applied and held in place for 48 hours. The day prior to the 2nd induction, 0.5ml of 10% sodium dodecyl sulfate in petrolactum was painted to the scapular area in order to cerate local irritation.

B. CHALLENGE EXPOSURE
Two weeks after the 2nd induction, a 2cm x 2cm lint patch saturated with 0.2mL of 25% test substance suspension in water was applied to the right flank of each guinea pig and the site was occluded for 24 hours. After this time, the patch was removed and the treated area was wiped with absorbent cotton dipped in tap water to remove residual test material.

The application sites were assessed for erythema and swelling 24 and 48 hours after removal of the patches and the applicaiton sites were scored as follows:

Grade Criteria:
0 No reaction
1 Slight reaction (edges of area not defined)
2 Moderate reaction (area well-defined)
3 Severe reaction.

OTHER:
All animals were observed daily for clinical signs of toxicity during the experimental period. The body weights of the animals were measured on the day of the first induction and on the challenge day.

Challenge controls:

5 animals per group were in the challenge control. These animals were treated with water instead of the substance during the induction phase.

Positive control substance(s):

not specified

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No test animals showed any signs of erythema or swelling 24 hours after challenge exposure.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No test animals showed any signs of erythema or swelling 24 hours after challenge exposure. .

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No test animals showed signs of erythem or swelling 48 hours after challenge exposure.

Remarks on result:

other: see Remark

Remarks:

Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No test animals showed signs of erythem or swelling 48 hours after challenge exposure. .

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

25%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

No signs of erythema or swelling in the control animals 24 hours after exposure to the challenge application.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: No signs of erythema or swelling in the control animals 24 hours after exposure to the challenge application. .

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

25%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

No signs of erythema or swelling in the control animals 48 hours after exposure to the challenge application.

Remarks on result:

other: see Remark

Remarks:

Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: No signs of erythema or swelling in the control animals 48 hours after exposure to the challenge application. .

There were no clinical signs of toxicity observed in any animal in either the test or control groups throughout the course of the study. In addition to this, all animals showed an increase in body weight on completion of the study.

Table 1: Results of the skin sensitization test of Aluminium magnesium titanium oxide:

Group		Aluminium magnesium titanium oxide - sensitized group				Aluminium magnesium titanium oxide - control group
Test substance used for induction treatment		Aluminium magnesium titanium oxide				Not applicable
Test substance used for challenge treatment		Aluminium magnesium titanium oxide				Aluminium magnesium titanium oxide
Induction: 1^stinduction (intradermal) 2^ndinduction (epidermal)		5% 25%				- -
Number of animals used		10				5
Challenge	Skin reaction	Number of animals used
		24 hrs		48hrs		24hrs		48hrs
		E	S	E	S	E	S	E	S
25%	0	10	10	10	10	5	5	5	5
	1	0	0	0	0	0	0	0	0
	2	0	0	0	0	0	0	0	0
	3	0	0	0	0	0	0	0	0

E=erythema

S=swelling

0=No reaction

1=Slight

2=Moderate

3=Severe.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

No evidence of skin senisitisation was seen under the conditions of this study.

Executive summary:

The potential of aluminium magnesium titanium oxide to act as a skin sensitiser was determined in a study conducted in accordance with the Magnusson and Kligmann method. Female guinea pigs were sensitised with 5% test substance in the 1st induction, 25%

suspension in water in the 2nd induction and were then exposed to a challenge 2 weeks after the 2nd induction, in which a 25%

suspension in water was applied for a 24 hour exposure period. Skin reactions were made 24 and 48 hours after the challenge period.

No positive skin reactions were recorded in any test animal 24 or 48 hours after the challenge exposure.

Under the conditions of the study, aluminium magnesium titanium oxide is not classified as a skin sensitizer and does not require classification according to Regulation (EC) No. 1272/2008.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A negative study is available for the read-across substance aluminium magnesium titanium oxide. The read-across substance and the registered substance are comparable insoluble ceramic substances. The read-across substance additionally contains magnesium which is not associated with skin sensitising properties. The induction of skin sensitisation is dependent on the binding of chemical components to skin proteins. Given the fact that the registered substance is an insoluble ceramic, the induction of skin sensitisation is not biologically plausible. Additionally the component ions of the substance (i.e. Al, Ti) are not associated with skin sensitisation.

Migrated from Short description of key information:
A negative study of skin sensitisation is available for the read-across substance aluminium magnesium titanium oxide.

Justification for selection of skin sensitisation endpoint:
Only one study is available for this endpoint.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

No data are available for respiratory sensitisation, but this would appear not to be biologically plausible based on the physicochemical properties (i.e. insolubility) of the substance.

Migrated from Short description of key information:
No data are available for respiratory sensitisation.

Justification for classification or non-classification

Classification for skin sensitisation is not proposed in the absence of any data indicating that the substance is a skin sensitiser. No data are available for respiratory sensitisation, but this would appear not to be biologically plausible based on the physicochemical properties of the substance.